B • TURBULENT FLOW 



the transition region, the recovery factor varies from the lower laminar 

 value to the higher turbulent value. An increase of the turbulent recovery 

 factor with the Reynolds number in the fully turbulent region predicted 

 by the theoretical formula of Seban [14], 



fe = 1 - (4.71 - 4.115 - 0.601P/-)i2e-o-2 



B = 



Pr bPr + 7 



2 5Pr + 1 



and the theoretical formula of Shirokow [15], 



re = 1 - 4.55(1 - Pr)Re-°-^ 



is not systematically detectable from the experimental results of Fig. 

 B,9a and B,9b. Here Re is the Reynolds number based on the distance 



> 



o 

 o 



<u o 



CD 



a 

 £ 



0.96 

 0.94 

 0.92 

 0.90 

 0.88 

 0.86 



0.84 



0.2 0.4 0.6 0.8 1.0 2 4 



Reynolds number X lO"*^ 



8 10 



Fig. B,9b. Variation of the temperature recovery factor with the Reynolds number 

 in the case of a flat plate, after Stalder, Rubesin, and Tendeland [13], Me = 2.4. 

 The Reynolds number xUe/ve is based on the conditions at the edge of the boundary 

 layer and on the distance from the leading edge. 



from a leading edge. There is probably also some slight variation of the 

 recovery factor with the Mach number. The measurements of Mack [12] 

 show a slight increase of the recovery factor with the Mach number, 

 while those of Stine and Scherrer [16] show no variation. The Mach num- 

 ber effect predicted by the theoretical formula of Tucker and Maslen [17], 



^ ]\r + 1 + 0.528M'^ 

 ^^ 3iV + 1 + M2 



N = 2.6Rei 



is not yet verified by experiments. According to Fig. B,9a and B,9b, the 

 turbulent recovery factors on cones and flat plates are of the same order, 



(94) 



